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We propose a novel long-period grating (LPG) based on a ring-core hollow fiber (RCHF) filled with functional liquid as a tunable material. The RCHF structure is simple. The effective refractive index tuning characteristics of the liquid-filled RCHF-LPG are investigated. The RCHF-LPG functions as a tunable device filling with a functional liquid. The temperature sensitivities of three RCHF-LPG samples filled with dimethylacetamide (DMA) or DMA–glycerin mixtures are measured. The results show that the sample with high-RI liquid has higher sensitivity to temperature variation. The maximum linear sensitivity of the temperature can reach −618 pm/°C.

In this work, Na+ ions doping into the Yb-doped fiber was proposed to improve the photo-darkening resistance. The results show that the photo-darkening induced excess loss at 702 nm was 37.26dB/m at equilibrium state. More than 50% excess loss was reduced comparing to Yb-doped fiber without Na+ ions.

The internet of things (IoT) technology has great potential in obtaining, analyzing, processing, controlling and feeding back the information of entity properties (location, status, behavior, characteristic, etc.), which will play an active role in promoting the development of smart grid. In this paper, we apply the IoT technology in the smart grid field. A kind of system architecture of smart grid is built according to the IoT system architecture. The system architecture of smart grid is divided into three layers -- the perception layer, the communication layer and the application layer. The application of IoT technology in every layer of the system architecture of the smart grid is analyzed and discussed in detail. Finally, the application prospect and problems which should be solved are forecast. It is found that the IoT technology will make smart grid more efficient, more intelligent, more secure and more convenient.

3G communication technology has three main wireless interface standards which are WCDMA, CDMA2000 and TD-SCDMA. The 3G devices and software of devices are different between different manufacturers and standards. In order to manage the different devices and many users in the training process of vocational education in communication profession, we designed and developed the software, “comprehensive communication network training platform”. Combining the device controlling software, this software packed the communication devices and users into a platform for unified management with some key technologies such as soft routing, Network Address Translation (NAT). Giving full consideration to the training process, the software can not only meet the requirements of vocational training, but also deploy the communication devices, resources and protect the security of the devices, so it is of great significance to the professional teaching of the mobile communication.

An innovative method based on support vector machines is presented to diagnose the fault of analog circuit. Firstly, in order to get enough fault samples, the circuit program is compiled in MATLAB software to obtain expressions of output signals. Secondly, fault samples are sent into Support Vector Machines to train Support Vector Machines. Thirdly, the test samples are classified by trained Support Vector Machines. Finally, an example of analog circuit fault diagnosis is provided. The result shows that this method has the advantages of simple algorithm, high efficiency, high accuracy, great capability in generalization and classification.